WW1: 'Tunneller John Chadwick told of explosion that sent the ground '300ft in the air'

DEEP underground in the black of a tunnel leading towards the German defences – Sergeant John Chadwick held his breath and listened carefully.

Close by, he could hear the unmistakable sound of picks and shovels working in a similar tunnel, being dug out in the direction of the British lines.

Using his skills and experience, he tried to estimate the direction the enemy tunnel was taking and the speed they were working at.

Sergeant Chadwick, a miner from Smallthorne before the outbreak of the Great War, knew exactly what the sound meant – a party of German sappers were working close by, intent on blowing up the British position and wiping out as many soldiers as possible.

Working underground was hot, unpleasant and dangerous at the best of times.

Tunnellers faced the constant threat of being buried by alive by a mine collapse, poisoned by carbon monoxide, or killed by an underground explosion.

Now Sergeant Chadwick, a Royal Engineer serving with the 175th Tunnelling Company, was waiting in the darkness with the added knowledge that, just yards away, was a platoon of enemy soldiers, intent on killing him.

The time was 12.30am on August 25, 1915 – and the danger was mounting by the second.

At any moment the walls of the British tunnel could collapse as the Germans burrowed through, prompting a desperate battle for survival in the dark, claustrophobic underground.

Or, if the Germans were aware of just how close they were to the English troops, they could pack the end of their tunnel with explosives, blowing through to the British side, then follow that up by charging their dazed opponents.

A platoon of infantryman appeared over his shoulder and took cover, rifles pointed at the end of the tunnel, should the enemy break through.

Sergeant Chadwick and the other Royal Engineers on duty with the 175th Tunnelling Company were also ready for action.

After a wait of what must have seemed hours, a major and staff colonel entered the cramped enclosure.

A decision was taken to take the roof off the dugout at the end of the British tunnel and bore a hole over the spot where the nearby Germans were digging.

If successful, and carried out without alerting the enemy, that would give the British troops the advantage.

A charge, known as a camouflet – a word taken from French mining technology – could be placed above the German miners.

This was a small, controlled underground blast designed to kill the enemy tunnellers without breaching the surface.

The order was given – 'work silently'.

But after digging five feet into the earth, the engineers hit gravel containing flint, a hard rock which could not be picked out with a boring tool.

There was only one thing to do – smash through and blow the tunnel as quickly as possible.

Speed was now of the essence, if the Germans were not aware of the nearby Royal Engineers already, they certainly would be when the tunnellers started smashing through the flint.

Sergeant Chadwick went to the rear of the tunnel to retrieve an iron bar an officer could remember discarding earlier in the evening.

All pretence of silence was now dropped as he used it to smash into the flint, again and again.

The hole was bored and charged with 50lb of explosives – enough to decimate the Germans, but not to blow through to the surface.

The order was given to fire the charge – nothing happened. After five minutes, sergeant Chadwick suggested boring through the tamping, the material which had been packed into the hole around the explosive charge.

Not knowing what the Germans were doing to counter the actions of the engineers, sergeant Chadwick smashed in the metal case containing the explosive charge. A smaller charge was rammed into it, to ignite the existing explosive.

Once again the engineers, officers and infantrymen all anxiously waiting underground took cover. This time, when the order was given, a huge explosion ripped through the tunnels – lifting up the earth around 300 ft into the surface above.

When the dust cleared the British trench above had been completely obliterated. In its place was a huge 40ft crater.

The size and range of the explosion took all the British soldiers by surprise and it was the company major who came up with the answer.

The British charge had detonated an enemy mine planted by the tunnelling Germans.

Only the speed and stealth of the Royal Engineers had prevented the enemy from beating them to lighting the explosion.

Had the Germans been quicker on that day, they would have set their own charge and blown the tunnel while the engineers were still working.

As it was, Sergeant Chadwick survived to continue fighting the secret, underground war that was being fought beneath the trenches all across the Western Front.

Describing the action in a letter home to a Mr MacGowan, manager of the Norton Colliery, which was printed in The Sentinel, Sergeant Chadwick said: "We got the hole bored and charged it with 50lb of explosive. Then the order came to 'fire'. Five minutes elapsed and no report. Something was wrong.

"We went back out and at my suggestion the order was given to bore the tamping out. This we did and we got down to the metal case containing the charge.

"I smashed in the top of the case and found it contained powder. We lowered a small charge, rammed and fired. This time it was successful. The ground lifted up at least 300ft.

"Everybody was surprised and the major said we had exploded an enemy mine. Instead of looking out for smoke, we were looking out for shelter.

"Then I got a sandbag from the parapet, but it did not stop me going back and crawling into the crater, a great hole about 40ft in diameter.

"The whole of our trench had disappeared. The spot was where four trenches met.

"It was very exciting work, but it was a pleasure to be in the officers' company."

For the action he modestly described, Sergeant Chadwick and acting Corporal Howell, also of Smallthorne, were both awarded the Distinguished Conduct Medal (DCM).

Although their are a number of John Chadwicks listed among the dead of the First World War, there is no record of a Sergeant Chadwick who served with the Royal Engineers, on the Commonwealth War Graves Commission's list of the fallen.

From that it can be assumed that Sergeant Chadwick was one of the lucky ones who returned home to his native Smallwood.

There are two candidates for the identity of Sgt Chadwick on the 1911 census. The first John Chadwick was living at 8 Lord Street, Smallthorne in 1911, eldest son of James and Elizabeth Chadwick.

He was a single man was employed as a coal miner shot lichter. In 1915 he would have been aged 29.

The second was also a miner, married to Mary Ellen Chadwick, and in 1911 had two children, nine-year-old Elizabeth and John, aged nine-months old when the census was carried out. He would have been aged 33 in 1915.